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Sierra is the leading platform for customer-facing AI agents, serving major brands like The GAP, Rocket Mortgage, SoFi, Sutter Health, and SoftBank. Founded by Bret Taylor (former Salesforce co-CEO, Facebook CTO, Google Maps co-creator) and Clay Bavor (18 years at Google, led Google Labs and AR/VR initiatives), Sierra is transforming how enterprises deploy AI agents across customer touchpoints.
In this role, you'll own the Channels and Experiences team, building the infrastructure that powers AI voice, chat, and messaging agents across phone calls, SMS, WhatsApp, email, and in-app experiences. You'll work on several critical frontiers:
**Multi-modal Conversations**: Enable seamless transitions between voice, text, and visual channels. Customers can start a call, switch to typing, send photos, and receive forms—all within one continuous conversation that the agent remembers and personalizes.
**Voice Quality at Scale**: Make AI agents sound and feel like real conversations across global carrier networks, telephony infrastructure, and contact centers. This requires solving latency, naturalness, and reliability for millions of concurrent calls.
**Personal Agent Protocol**: Help build an open standard that allows personal AI assistants (like ChatGPT) to safely interact with company agents and customer accounts, without requiring full account access.
**Native App Integration**: Develop ChatKit, Sierra's library of native iOS, Android, and web components for voice controls, live waveforms, transcripts, and chat. Shape how agents appear inside customer flagship apps.
**Global Telephony Stack**: Own the infrastructure for routing millions of calls and messages to the right agent. Work with SIP, WebRTC, Sierra's proprietary Voice Protocol, and integrations with major contact-center platforms.
**Channel Expansion**: Build tools that let developers launch new channels (SMS, WhatsApp, RCS, email, LINE, Messenger, Instagram) in hours, not weeks.
You'll operate in a high-autonomy, AI-native culture where shipping fast, obsessing over details, and solving hard problems (protocols, edge cases, end-to-end experiences) are core. You'll work across backend, infrastructure, mobile, and web, and you'll be expected to use AI tools as a fundamental part of how you work and think.
**Requirements**:
- 4+ years hands-on experience building production systems that real users depend on
- Degree in Computer Science or related field, or equivalent professional experience
- Strong backend fundamentals with comfort across backend, infra, mobile, and web
- Passion for frontier AI products and reliable, maintainable, secure systems at scale
- High agency and motivation to drive outcomes independently
**Preferred Experience**:
- Building AI products for enterprise or consumer markets
- Native SDK development for iOS (Swift) or Android (Kotlin)
- Messaging apps, voice apps, or voice agent development
- SIP, WebRTC, Twilio, or contact-center platform experience
- Real-time, low-latency distributed systems
